1. Field of the Invention
The present invention relates to the field of liquid crystal displaying, and in particular to a novel light guide plate for backlight module and a manufacturing method thereof.
2. The Related Arts
Liquid crystal display (LCD) has a variety of advantages, such as thin device body, low power consumption, and being free of radiation, and is thus widely used. Most of the LCDs that are currently available in the market are backlighting LCDs, which comprise a liquid crystal panel and a backlight module. The operation principle of the liquid crystal panel is that liquid crystal molecules are interposed between two parallel glass substrates and a plurality of vertical and horizontal fine electrical wires is arranged between the two glass substrates, whereby the liquid crystal molecules are controlled to change direction by application of electricity in order to refract light emitting from the backlight module for generating images. Since the liquid crystal panel itself does not emit light, light must be provided by the backlight module in order to normally display images. Thus, the backlight module is one of the key components of an LCD. The backlight module can be classified in two types, namely side-edge backlight module and direct backlight module, according to the position where light gets incident. The direct backlight module arranges a light source, such as a cold cathode fluorescent lamp (CCFL) or a light-emitting diode (LED) at the back side of the liquid crystal panel to form a planar light source that directly provides lighting to the liquid crystal panel. The side-edge backlight module arranges a backlight source of LED light bar at an edge of a back panel to be located rearward of one side of the liquid crystal panel. The LED light bar emits light that enters a light guide plate (LGP) through a light incident face of the light guide plate and is projected out through a light emergence face of the light guide plate, after being reflected and diffused, to thereby transmit through an optic film assembly and form a planar light source for the liquid crystal panel.
In a side-edge backlight module, the light guide plate is a necessary component. The light guide plate is often made of polymethylmethacrylate (PMMA) or polyacrylate organic-inorganic nano-composite material (MS material). The light guide plate has a bottom surface on which ink dots are formed to destruct total reflection of light in order to allow light to be projected out of the light emergence face of the light guide plate. As shown in FIG. 1, the commonly used ink dots 120 are formed by applying printing techniques to print ink on a surface of a body 100 of the light guide plate.
Since the light guide plate are in contact with a reflector plate and optic films within the backlight module and since the light guide plate has a relatively high resistance of which the volume resistivity is 10-15 Ohm·cm. Thus, the light guide plate can easily induce static electricity. As shown in FIG. 2, due to electrostatic attraction, mura (speckles, which are various marking and trace caused by non-uniform brightness of display) when the liquid crystal panel is displaying an image.